<div id="map"></div>
*{padding:0;margin:0;}
html,body{width:100%;height:100%;}
#map { background: #111; height: 100%;}

.leaflet-tile{ 
  transform: scale(0);
}
.leaflet-tile.leaflet-tile-loaded{
  transform: scale(1);
  transition:0.5s transform ease-in;
}
var map = new L.Map('map', {
  center: new L.LatLng(52.520, 13.385),
  zoom: 14
}),
  layer = L.tileLayer('http://{s}.basemaps.cartocdn.com/light_nolabels/{z}/{x}/{y}.png',{
  attribution: '&copy; <a href="http://www.openstreetmap.org/copyright">OpenStreetMap</a> contributors, &copy; <a href="http://cartodb.com/attributions">CartoDB</a>'
});
			    
map.addLayer(layer);

External CSS

  1. https://cdn.leafletjs.com/leaflet-0.6.4/leaflet.css

External JavaScript

  1. https://cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.min.js
  2. https://cdnjs.cloudflare.com/ajax/libs/leaflet/0.6.4/leaflet.js